"If even one part of our continent lives under a tyrannical regime, none of us can claim to be free. The Swazi people have suffered economically and politically at the hands of the royal elite," said spokesperson Tahir Sema in a statement.
"It is heartening to note that there is a new mood amongst trade unions, civic and social movements, students and faith based organisations.
"They have realised that it is only through mobilising their members, and daring to think and plan for another Swaziland that the current bankrupt regime can be replaced."
Samwu supported the call of trade unions in Swaziland for the sacking of the current cabinet and King Mswati and replacing them with a transitional government.
"We therefore send our greetings to all Swazi democrats, and pledge ourselves to providing practical solidarity to them in the struggle for a democratic and people driven Swaziland."
ANC ally Cosatu is set to protest along the Swaziland border on Tuesday. Unions, youth movements, civil society and opposition groups have reportedly vowed to protest on Tuesday against the Swazi monarch.
A former leader of the Swaziland National Union of Students said the youth were to embark on North African-style protests on April 12 - they are demanding a "total change of the system of government in Swaziland".
A facebook group called the "April 12 Swazi Uprising" had been started to help mobilise people.
According to its description on Facebook, the group: "is the voice of the people on the streets who are sick and tired of the misrule by the Swazi regime and the snail pace and lack of action by Swaziland's so-called progressive".
It pledges to, in the next few months, create the biggest mass movement that the country had ever seen.